Locally advanced prostate cancer: Biochemical results from a prospective phase II study of intermittent androgen suppression for men with evidence of prostate‐specific antigen recurrence after radiotherapy

Abstract

In the article by Bruchovsky et al.,1 intermittent androgen suppression was evaluated in patients with clinically locally advanced prostate cancer who developed biochemical disease recurrence after radiotherapy. We consider it to be of utmost important to improve currently existing knowledge regarding intermittent androgen suppression, which could be a feasible approach as adjuvant or salvage therapy for prostate cancer in selected patients. The authors concluded that the baseline and nadir levels of prostate-specific antigen are major predictors of response to androgen suppression. Nevertheless, it was not clear whether patients suspected of having local disease recurrence rather than systemic disease recurrence2 (and who therefore had disease that was amenable to local salvage treatment with curative intent rather than androgen suppression) were excluded from this analysis.3 Furthermore, it is unclear which definition of biochemical disease recurrence after radiotherapy was considered by the authors because false diagnoses of biochemical disease recurrence are not infrequent in prostate cancer patients who are treated with radiotherapy.4 We believe that including patients with local disease recurrence or a false diagnosis of biochemical disease recurrence could have biased the results of the study by Bruchovsky et al. Finally, it is important to remember that the combination of cyproterone acetate and gonadotropin-releasing hormone (Gn-RH) analogue is reported to have a significantly more unfavorable outcome compared with the use of Gn-RH alone and an even worse outcome compared with maximum androgen blockade with nilutamide or flutamide.5